Active ingredient delivery system

Abstract

A spray-chilled particulate delivery system that has a crystalline matrix structure and comprises a volatile hydrophobic active ingredient and a carrier material selected from the group consisting of erythritol and mannitol and mixtures thereof wherein, relative to the total weight of the carrier material, 75% or more of the carrier material is in crystalline form. The process for preparing the delivery system comprises the steps of (i) forming a melt of a carrier material selected from the group consisting of erythritol and mannitol and mixtures thereof (ii) incorporating a volatile hydrophobic active ingredient into the melt (iii) forming a melt-mixture comprising an emulsion, dispersion or suspension of the volatile hydrophobic active ingredient in the melt (iv) forming discrete particles of the melt mixture, and (v) cooling the discrete particles, so as to form the crystalline delivery system.

What is claimed is: 
     
         1 . A spray-chilled particulate delivery system, the particulate delivery system comprising a crystalline structure and comprising (i) a carrier material selected from the group consisting of erythritol and mannitol and mixtures thereof, and (ii) a volatile hydrophobic active ingredient that is liquid at wherein, relative to the total weight of the carrier material, 75% or more of the carrier material is in crystalline form. 
     
     
         2 . The delivery system according to  claim 1  wherein the carrier material is erythritol. 
     
     
         3 . The delivery system according to  claim 1  wherein the active ingredient is, at least partly, included within crystals of the carrier material. 
     
     
         4 . The delivery system according to  claim 1 , wherein the particles have an average means diameter of 5 to 4000 microns. 
     
     
         5 . The delivery system according to  claim 1  having a freely settled density of 0.7 g cm −3  to 1.35 g cm −3 . 
     
     
         6 . The delivery system according to  claim 1  wherein the active ingredient is liquid, when measured at 45° C. and 1 atmosphere. 
     
     
         7 . A process for preparing a particulate delivery system having a crystalline structure comprising the steps of:
 (i) forming a melt of a carrier material selected from the group consisting of erythritol and mannitol,   (ii) incorporating a volatile hydrophobic active ingredient into the melt,   (iii) forming a melt-mixture comprising an emulsion, dispersion, solution or suspension of the volatile hydrophobic active ingredient in the melt,   (iv) forming discrete particles of the melt mixture, and   (v) cooling the discrete particles,   
       so as to form a particulate delivery system in which, relative to the total weight of the carrier material, 75% or more of the carrier material is in crystalline form. 
     
     
         8 . A process according to  claim 7  wherein the melt-mixture of step (ii) is supercooled prior to forming the discrete particles in step (iii). 
     
     
         9 . A process according to  claim 7  wherein the melt-mixture of step (iii) comprises 10 wt % or less of water, relative to the total weight of the melt mixture. 
     
     
         10 . A process according to  claim 7  wherein the cooling step comprises heat removal at a rate of greater than about 600 kJ.kg −1 .min −1 . 
     
     
         11 . A process according to  claim 7  wherein the particulate delivery system is further encapsulated.